Reactive dyes containing piperazine

ABSTRACT

Reactive dyes containing piperazine have formula (I)                    
     wherein: each of D 1  and D 2 , independently, is a chromophoric group; each of R 1 , R 2 , R 3  and R 4 , independently, is H or an optionally substituted alkyl group; each of X 1  and X 2 , independently, is a labile atom or group; each of x and y, independently is 0 or 1 and at least one of x and y is 1; each of a and b independently, is 1 to 5; the or each R 5 , independently, is alkyl; and z is 0 to 4. For colouration of a substrate the dyes can be applied at a pH above 7 by, for example, exhaust dyeing, padding or printing.

This invention relates to reactive azo dyes containing piperazine.

EP-A-0126265 discloses a range of reactive azo dyes of the formula (A).

wherein

D is a residue of a benzene- or naphthalenesulphonic acid which isoptionally further substituted;

R¹ is hydrogen, C₁₋₁₀-alkyl, cycloalkyl, benzyl or a group C₂H₄OR⁴,C₂H₄—OC₂H₄OR⁴, C₃H₆OR⁴ or CH(CH₃)CH₂OR⁴ (in which R⁴ is C₁₋₄alkyl);

R² is a group R¹ or is an optionally substituted sulpho-free, phenylgroup;

R³ is hydrogen, methyl, methoxy, chloro or sulfo and

n is 1 or 2. When n=1, X is at least one reactive group and when n=2, Xis a group of the formula

—X¹—B—X²—

 in which each of X¹ and X² is a reactive group such as a triazine and Bis a linking bridge derived from an amine. In one example (Compound192), the linking bridge is derived from 2-aminoethylpiperazine.Compound 192 has the formula (20)

It is to be noted especially that the disclosure of EP-A-0126265explicitly excludes components wherein each of R¹ and R² is hydrogen atthe same time.

GB-A-1283771 discloses a range of reactive disazo dyes of the formula(B)

where D is a naphthylazo-phenylene or -naphthalene containing at least 3sulphonic acid groups, R is H or an optionally substituted C₁₋₄ alkylgroup and X is specifically a phenylene, diphenylene or naphthalenenucleus. They offer a degree of fixation over a wide range of liquor togoods ratios and provide shades of very good light fastness.

We have found surprisingly that if in dyes generally of this type, thegroup X is an asymmetrical amino piperazine derivative thereof asdefined below, such dyes, especially when used for exhaust dyeing ofcellulosic materials, can exhibit excellent properties, includingbuild-up, aqueous solubility, light-fastness, wash-off and robustness toprocess variables.

According to one aspect, the present invention provides a dye of theformula (I)

wherein:

each of R¹, R², R³ and R⁴, independently, is H or an optionallysubstituted alkyl group;

each of X¹ and X², independently, is a labile atom or group;

each of x and y, independently, is 0 or 1 and at least one of x and y is1;

each of a and b, independently, is 2 to 5;

when each of x and y is 1, a>b;

the or each R⁵, independently, is alkyl;

z is zero or is 1 to 4; and

each of D¹ and D², independently, is a monoazo or polyazo chromophore,or a metallized derivative thereof, provided that the dye of the formulaI is other than a dye of the formula (20), given above.

In one preferred range of dyes embodying the invention, each of x and yis 1, in which case, more preferably, each of a and b, independently, is2 or 3.

In an alternatively, even more preferred embodiment, x is 0 and y is 1,in which case, more preferably, b is 2 or 3.

The piperazine nucleus is preferably unsubstituted (z=zero) orsubstituted in one or both of the 2- and 5- positions, more preferablywith methyl or ethyl.

Preferred values of X¹ and X² are halogen, especially fluorine andchlorine, and a pyridinium salt, most typically a 3- or 4- carboxypyridinium salt derived respectively from nicotinic and isonicotinicacid.

Each group R¹-R⁴, independently, is preferably H or C₁₋₄ alkyl, forexample, methyl, ethyl or propyl, which C₁₋₄ alkyl group is optionallysubstituted, for example, by a hydroxy group.

Preferred chromophoric groups D¹ and D² are monoazo, disazo and otherpolyazo dyes, which, more preferably contain at least one sulphonic acidgroup. Especially preferred dyes contain at least one monoazo or atleast one disazo chromophoric group D¹ or D². The groups D¹ and D², evenif each is a monoazo or each a disazo chromophore, may be the same as,or different from, one another. The use of different respectivechromophores D¹ and D² allows the synthesis of a range of new yellows,reds and navies and, for example, when chromophore D¹ would provide ayellow dye and D² a blue dye, a new homogenous green dye may beobtained.

In a preferred range of monoazo dyes, each of D¹ and D², independently,is an optionally metallized monoazo chromophore of the formula (i)

A—N═N—E  (i)

wherein:

one of A and E is attached to the reactive triazinylamino group;

A is derived from a diazotizable amine; and

E is derived from a coupling component.

In a preferred range of dyes of the formula (i), A is an optionallysubstituted aryl group and when A is attached to the triazinylaminogroup, the attachment may be from the aryl group or from a substituentthereon;

E is an optionally substituted aryl or heteroaryl group and when E isattached to the triazinylamino group the attachment may be from the arylor heteroaryl group or from a substituent thereon, or E is anacetoacetamidoaryl group wherein the aryl moiety is optionallysubstituted and wherein the azo linkage in the formula (i), given anddefined above, is linked to the methylene group of theacetoacetamidoaryl group and when E is attached to the triazinylaminogroup the attachment may be from the aryl moiety or from a substituentthereon.

In one, more preferred, range of dyes of formula (i) in which the groupA is attached to the triazinylamino group in formula (I), given anddefined above,

A is a phenyl or naphthyl group;

which said phenyl or naphthyl group is optionally substituted by analkyl (preferably C₁₋₄ alkyl), phenyl, naphthyl or amino- (which maybear a C₁₋₄ alkyl group), amido- or sulphonamido-phenyl or naphthylgroup and A may be attached to the triazinylamino ring from the saidsubstituent alkyl, phenyl or naphthyl group or phenyl or naphthyl moietyof the said substituent;

which said phenyl or naphthyl group of A is additionally optionallysubstituted by an alkyl (preferably C₁₋₄alkyl), alkoxy, (preferablyC₁₋₄alkoxy) or halo (preferably chloro) group or a carboxylic acid orsulphonic acid group or a salt thereof; and

E is an aryl or heteroaryl group selected from phenyl, naphthyl,pyrazolyl, pyrazolonyl, pyridyl, pyridonyl and pyrimidinyl groups or isan acetoacetamidoaryl group;

which said aryl or heteroaryl group is optionally substituted at leastso as to provide the coupling component from which the group E isderived with sufficient electron donating capacity to allow the saidcoupling (in general, when E is a pyridyl or pyrimidinyl group, thepresence of at least one electron donating group is necessary to allowcoupling); and

which said aryl moiety of the acetoacetamidoaryl group is optionallysubstituted preferably by at least one of alkyl, alkoxy, halo, H₂NCONH,CH₃CONH or SO₃H (or a salt thereof), more preferred alkyl and alkoxybeing C₁₋₄alkyl and C₁₋₄ alkoxy.

In the above dyes, especially when E is an a-naphthol group, the dye isoptionally metallized.

When the group E is a phenyl or naphthyl group, still more preferablythis is optionally substituted by an alkyl (preferably C₁₋₄alkyl),alkoxy (preferably C₁₋₄alkoxy), ureido, acylamino (preferablyC₂₋₅acylamino), alkyl (preferably C₁₋₄alkyl) sulphonyl, halo (preferablychloro), hydroxyl or amino group, which amino group is optionallysubstituted by at least one (preferably C₁₋₄) alkyl group, or is acarboxylic or sulphonic and group or a salt thereof.

When the group E is a pyrazolyl, pyrazolonyl, pyridyl, pyridonyl orpyrimidinyl group, still more preferably this is substituted by ahydroxyl, mercapto or amino group, which amino group is optionallysubstituted by at least one (preferably Coo) alkyl group.

In one especially preferred range of such dyes, E is anacetoacetamidoaryl group and A is an optionally substituted phenylenegroup such that at least one of D¹- and D²- is a chromophore of theformula (iv)

wherein:

B is an optionally substituted aryl group;

the or each R⁶, independently, is alkyl, alkoxy, halo, H₂NCONH, CH₃CONHor SO₃H (or a salt thereof);

R¹¹ is hydrogen or alkyl;

p is zero or 1-4, more preferably zero or 1-3, still more preferably 0,1 or 2, especially 1 or 2.

For the avoidance of doubt it is confirmed that in the above formula (ivand subsequent formulae, the unsubstituted bond {circle around (1+L )}indicates a link to a triazinylamino group in the formula (I).

Preferred alkyl groups of R⁶ and R¹¹ are C₁₋₄alkyl groups and preferredalkoxy groups of R⁶ are C₁₋₄alkoxy.

Preferred aryl groups of B are phenyl and naphthyl, optionallysubstituted by alkyl (more preferably C₁₋₄ alkyl, especially methyl),alkoxy (more preferably C₁₋₄alkoxy, especially methoxy), chloro, nitro,amido or sulphonic acid (or a salt thereof).

In an alternative, more preferred, range of dyes of the formula (i), inwhich the group E is attached to the triazinylamino group in formula(I), given and defined above,

A is a phenyl or naphthyl group, optionally substituted by at least oneof an alkyl (preferably C₁₋₄alkyl), halo (preferably chloro), cyano,hydroxy, aryloxy (preferably phenoxy), alkylsulphonyl (preferablyC₁₋₄alkylsulphonyl), or arylsulphonyl (preferably phenylsulphonyl) groupor a carboxylic or sulphonic acid group or a salt thereof; and

E is an optionally substituted aryl or heteroaryl group selected fromphenyl, naphthyl, pyrazolyl, pyrazolonyl, pyridyl, pyridonyl andpyrimidinyl groups or is an acetoacetamidoaryl group,

which said aryl or heteroaryl group or aryl moiety of theacetoacetamidoaryl group is optionally substituted by an alkyl(preferably C₁₋₄alkyl), phenyl, naphthyl or amino- (which may bear aC₁₋₄ alkyl group), amido- or sulphonamido-phenyl or naphthyl and E maybe attached to the triazinylamino group from the said substituted alkylgroup, phenyl or naphthyl group or phenyl or naphthyl moiety of the saidsubstituent,

which said aryl or heteroaryl group is further optionally substituted atleast so as to provide the coupling component from which the group E isderived with sufficient electron donating capacity to allow the saidcoupling (in general when E is a pyridyl or pyrimidinyl group, thepresence of at least one electron donating group is necessary to allowcoupling); and

which said aryl moiety of the acetoacetamidoaryl group is optionallysubstituted, preferably by at least one of alkyl, alkoxy, halo, H₂NCONH,CH₃CONH or SO₃H (or a salt thereof), more preferred alkyl and alkoxybeing C₁₋₄ alkyl and C₁₋₄, alkoxy.

In the above dyes, especially when A is an a-naphthol, the dye isoptionally metallized.

When the group E is a phenyl or naphthyl group, still more preferablythis is optionally substituted by an alkyl, alkoxy (preferablyC₁₋₄alkoxy), ureido, acylamido (preferably C₂₋₅acylamido),alkylsulphonyl (preferably C₁₋₄alkylsulphonyl), halo (preferablychloro), hydroxyl or amino group, which amino group is optionallysubstituted by at least one alkyl group (preferably C₁₋₄alkyl), or is acarboxylic or sulphonic acid group or a salt thereof.

When the group E is a pyrazolyl, pyrazolonyl, pyridyl, pyridonyl orpyrimidinyl group, still more preferably this is substituted by ahydroxyl, mercapto or amino-group, which amino-group is optionallysubstituted by at least one (preferably C₁₋₄) alkyl group.

In an especially preferred range of such dyes, A is an optionallysubstituted phenyl or naphthyl group (Ar) and E is an acetoacetamidoarylgroup such that at least one of D¹- and D²- is a chromophore of theformula (iii)

wherein: each of R⁶, R¹¹ and p, is as defined above; and

Ar is optionally substituted phenyl or naphthyl or is a chromophore,such as an azo, especially monoazo dye.

Substituents which may be on the phenyl or naphthyl group or chromophoreare alkyl (more preferably C₁₋₄ alkyl, especially methyl), alkoxy (morepreferably C₁₋₄ alkoxy, especially methoxy), chloro, nitro, amido orsulphonic acid (or a salt thereof.

Another preferred range of dyes of formula (i) in which the group E isattached to the triazinylamino group is a range in which, in at leastone, and more preferably each, of D₁ and D₂, E is an optionallysubstituted phenylene group such as to provide, in the dye, at least onechromophore of the formula (v)

wherein:

A¹ is a phenyl or naphthyl group, optionally substituted by at least oneof an alkyl (preferably C₁₋₄alkyl), halo (preferably chloro), cyano,hydroxy, aryloxy (preferably phenoxy), alkylsulphonyl (preferably C₁₋₄alkylsulphonyl), or arylsulphonyl (preferably phenylsulphonyl) group ora carboxylic or sulphonic acid group or a salt thereof; and

p and R⁶ are as defined above. Most of such chromophores will be yellowin colour, as will a dye in which each of D₁- and D₂- is of the formula(v).

In the chromophores of formula (v), p may be zero but when p is 1, 2, 3or 4, the or each R₆, independently, is alkyl (preferably C₁₋₄ alkyl),alkoxy (preferably C₁₋₄ alkoxy), halo, H₂NCONH, H₃CCONH or SO₃H (or asalt thereof). More preferably, p is 1, 2 or 3, especially 1 or 2, and astill more preferred range of such chromophores has the formula (vi)

wherein: A¹ is as defined above;

R⁷ is alkyl (preferably C₁₋₄ alkyl), alkoxy (preferably C₁₋₄ alkoxy),halo, H₂NCONH or H₃CCONH; and

R⁸ is H, alkyl (preferably C₁₋₄ alkyl), alkoxy (preferably C₁₋₄ alkoxy)or halo.

In an especially preferred range of chromophores of formulae (v) and(vi), R⁷ is H₂NCONH, and more especially R⁸ is then hydrogen.

In preferred ranges of chromophores of the formula (v), A¹ is anoptionally substituted phenyl or naphthyl group which, more preferably,is substituted by at least one SO₃H group, or a salt thereof. Still morepreferably, with reference to the formula (I), given and defined above,x is zero, y is 1 and b is 2 or 3.

Preferred starting materials for providing, a yellow chromophore of theformula (v) are (1) a diazotizable amine component capable ofdiazotization and coupling to a coupling component and (2) a couplingcomponent to which the diazotized amine component can couple and alsocontaining an amino group for reaction with a cyanuric halide,especially cyanuric chloride or fluoride, for attachment of thechromophore to the triazinylamino group.

Suitable diazo components are, for example, aniline, orthanilic acid,metanilic acid and sulphanilic acid, 2-aminobenzene-1,4-disulphonicacid, 2-aminobenzene-1,5-disulphonic acid,2-amino-5-methylbenzene-1sulphonic acid,2-amino-5-methoxybenzene-1-sulphonic acid, 2-aminobenzoic acid and3-chloro-4-aminobenzene-1-sulphonic acid and α- and β-naphthylaminessubstituted by at least one of sulphonic acid, carboxylic acid, halo,alkyl (especially C₁₋₄ alkyl), acylamino (especially C₂₋₅acylamino),cyano and aminoalkyl (especially amino C₁₋₄alkyl), such as2-aminonaphthalene-1-sulphonic acid, 2-aminonaphthalene-1,5-disulphonicacid, 2-aminonaphthalene-4,8-disulphonic acid and2aminonaphthalene-3,6,8-trisulphonic acid.

Suitable coupling components are, for example, 3-ureidoaniline,3acetylaminoaniline, and 2,5-substituted anilines in which one of therespective substituents, independently, is selected from methyl, methoxyand halo (especially chloro) and the other from methyl, methoxy andacetylacetamino.

The reaction may be carried out, for example, by diazotizing a diaminecomponent having one protected amine, coupling it to the couplingcomponent, releasing the protected amine, then reacting the resultantdyestuff firstly with a cyanuric halide, especially cyanuric chloride orfluoride, and then with an aminoalkylpiperazine. Alternatively, adiamine containing one hindered and one unhindered amine group may beallowed to react with an equivalent of cyanuric halide and the resultantproduct diazotized and coupled onto the coupling component prior tosubsequent reaction with the aminoalkylpiperazine.

In an especially preferred range of yellow dyestuffs, each of D¹- andD²- is a chromophoric group of the formula

A most preferred yellow dye has the formula (1)

In chromophores of the formula (v), E may be an optionally substitutedheteroaryl group such as a pyrazole, pyrimidine or a pyridine,especially a pyridone derivative which, when E is attached to thetriazinylamino group, is provided by an amino substituted derivativecapable of reaction with a cyanuric halide, especially cyanuric chlorideor fluoride, for attachment of the chromophoric group.

Thus, in yet another preferred range of chromophores of the formula (v)in which A is attached to the triazinylamino group, E may be anoptionally substituted heteroaryl group, for example, a group of theformula (vii)

wherein: p and R⁶ are as defined above;

X is OH or NH₂; and

R⁹ is methyl, carboxyl or methoxycarbonyl; or

wherein R¹²is hydrogen, C₁₋₄ alkyl or phenyl; R¹³ is hydrogen, CONH₂,CN, C₁₋₄alkyl or CH₂SO₃H; and R¹⁴ is C₁₋₄alkyl or phenyl; or

wherein each of P, Q and R, independently, is hydrogen, C₁₋₄alkoxy,hydroxy, C₁₋₄alkylthio, mercapto, amino, C₁₋₄alkylamino or(di-C₁₋₄alkyl)amino; and

wherein, in each of formulae (vii)-(ix), the bond {circle around (2+L )}is attached to the monoazo group.

In still another preferred range of dyes of formula (v) in which E isattached to the triazinylamino group, E is a heteroaryl or heteroaralkylgroup, for example, a heteroaryl group of the formula (x)

wherein p, R⁶, R⁹ and X are as defined above;

or E is a hetero or heteroaralkyl group of the formula (xi)

wherein R¹² and R¹³ are as defined above and q is zero or is 1-4; and ineach of formulae (x) and (xi), the bond {circle around (2+L )} isattached to the monoazo group.

In another preferred range of monoazo dyes, at least one of, and morepreferably, each of D¹ and D², independently, is a monoazo chromophoreof the formula (xii)

A¹—N═N—E¹  (xii)

wherein: A¹ is a phenyl or naphthyl group optionally substituted by atleast one of an alkyl (preferably C₁₋₄alkyl), halo (preferably chloro),cyano, hydroxy, aryloxy, alkylsulphonyl or arylsulphonyl group or acarboxylic or sulphonic acid group or a salt thereof; and

E¹ is a hydroxy naphthyl group, optionally substituted by at least onesulphonic acid group or a salt thereof, and optionally additionallysubstituted by halo, preferably chloro, hydroxyl, methyl or acylamino(preferably a C₂₋₅acylamino) group.

More preferably, the group A¹ is substituted by at least one SO₃H groupor a salt thereof, and also more preferably, the group El is substitutedby at least one group selected, independently, from SO₃H (and saltsthereof) and CH₃. Still more preferably, with reference to the formula(1), given and defined above, x is zero, y is 1 and b is 2 or 3.

In a more preferred range of dyes of the formula (xii), the group E hasthe formula (xiii)

or has the formula (xiv)

wherein, in each formula (xiii) and (xiv), the or each R¹⁵ is halogen,methyl, acylamino or SO₃H or a salt thereof and p is as defined above;and the bond (is attached to the monoazo group.

Preferred starting materials for providing a red or orange chromophoreof the formula (xiii) are, as mentioned above in relation to the yellowchromophores, diazotizable amine components and coupling componentshaving an amino group for reaction with a cyanuric halide.

Suitable diazo components are, for example, those mentioned above forthe yellow chromophores.

Suitable coupling components for the red or orange chromophores are, forexample, 1-amino-8-hydroxynaphthalene-3,6-disulphonic acid (H-acid),1-amino-8-hydroxynaphthalene-2,6-disulphonic acid (K-acid),2-amino-8-hydroxynaphthalene-6-sulphonic acid (y-acid) or thecorresponding N-methyl derivative (Me-y-acid),3-amino-8-hydroxynaphthalene-6-sulphonic acid(J acid) or thecorresponding N-methyl derivative (Me-J-acid),2-amino-8-hydroxynaphthalene-3,6disulphonic acid, (2R- or sulpho-y-acid)and 3-amino-8-hydroxynaphthalene-4,6-disulphonic acid (sulpho-J-acid).

Especially preferred red dyes have the respective formulae (2), (3) and(4):

In another preferred range of monoazo chromophores, at least one andmore preferably each of D¹- and D²-, independently, is a copperedmonoazo chromophore of the formula (xv)

wherein X¹ is a sulphonic acid group (or a salt thereof), a carboxylgroup (or a salt thereof), or an alkyl (preferably C₁₋₄alkyl) or alkoxy(preferably C₁₋₄alkoxy) group or a halogen (preferably chlorine) atom;

X² is a sulphonic acid group;

B¹ is an optionally substituted phenylene or naphthalene group linked tothe naphthalene nucleus either directly or through an optionalsubstituent and linked to the triazinylamino group either directly orthrough an optional substituent;

s is zero or is 1-4;

t is zero or is 1-3; and

u is zero or 1.

Most of such chromophores will be navy in colour, as will a dye in whicheach of D₁- and D₂- is of the formula (xv).

Preferred substituents linking the group B¹ to the naphthalene nucleusare C₁₋₄ alkylene, amino (optionally bearing a C₁₋₄ alkyl group), amidoand sulphonamido and other preferred substituents on B¹ are alkyl (morepreferably C₁₋₄ alkyl, especially methyl), alkoxy (more preferably C₁₋₄alkoxy, especially methoxy), chloro, nitro, amido or sulphonic acid (ora salt thereof).

More preferably, the coppered monoazo chromophore has the formula (xvi)

where X¹ and s are as defined above.

Preferred starting materials for providing a navy monoazo chromophore ofthe formula (xv) are diazotizable amine components containing a hydroxylor methoxy group available for metallization and a coupling componentalso having an amino group for reaction with a cyanuric halide,especially cyanuric chloride or fluoride, as well as a site orsubstituent available for metallization.

The choice of the diazotizable amine component and coupling componentmay depend upon the method of metallization employed. For example, ifmetallization is to be carried out by oxidative demethylation, thediazotizable amine component will have a methoxy group adjacent to theamino group and the coupling component will be an a-naphthol compound.Alternatively, if oxidative metallization is to be carried out, thediazotizable amine component will have a hydrogen atom adjacent to theamino group and the coupling component will be an a-naphthol compound.As another alternative, the diazotizable amine and coupling componentmay both have a hydroxyl group substituent so that, in the chromophore,respective hydroxyl groups are provided ortho to the azo linkage forcomplex formation with the metal.

Suitable diazotizable amine components for the navy chromophores are,for example, 1-hydroxy-2-aminobenzene-4-sulphonic acid,1-hydroxy-2-aminobenzene-4-(β-sulphatoethyl sulphonyl) benzene,1-hydroxy-2-aminobenzene-4,6-disulphonic acid,1-hydroxy-2-amino-4-methoxy-5-(β-sulphatoethylsulphonyl) benzene,1-amino-2-hydroxy naphthalene-4-sulphonic acid,1-hydroxy-2-amino-naphthalene-3,6-disulphonic acid,1-hydroxy-2-amino-naphthalene-4,8-disulphonic acid,1-hydroxy-2-amino-naphthalene-4,6,8-trisulphonic acid and1-hydroxy-2-amino-8-(β-sulphatoethylsulphonyl) naphthalene-6-sulphonicacid.

Suitable coupling components are, for example, H-acid and K-acid.

In a further alternative range of preferred dyes, each of D¹ and D² is adisazo chromophore, or a metallized derivative thereof. Suchchromophores may yield, for example dyes having an especially good deepblue or navy colour.

In one preferred range of disazo dyes, at least one and more preferablyeach of D¹ and D², independently, is a disazo chromophore of the formula(xvii)

A²—N═N—M—N═N—A³  (xvii)

wherein one of A² and A³ is attached to the triazinylamino group andeach of A² and A³, independently, is a phenyl or naphthyl group,optionally substituted by at least one group, independently, selectedfrom sulphonic acid (or a salt thereof), carboxylic acid (or a saltthereof, alkyl, acylamino (preferably C₂₋₅acylamino and especiallyacetylamino), halo, alkylsulphonyl and alkylsulphonylamino groups (whereeach alkyl group or moiety is preferably C₁₋₄ alkyl); and

M is a naphthalene group substituted by at least a hydroxyl and an aminogroup and optionally substituted by at least one sulphonic acid group.

Most of such chromophores will be navy in colour, as will a dye in whicheach of D₁ and D₂ is of the formula (xvii).

More preferably, M is a group of the formula (xviii)

where the sulphonic acid group in the 8-amino-substituted ring is in the5- or 6-position.

Preferred starting materials for providing a chromophore of the formula(xvii) are (1) a first diazotizable amino component for diazotizationand coupling to provide whichever of the groups A² and A³ is to providea terminal end of the dye remote from a triazinylamino group, (2) asecond diazotizable amino component having one amino group (or a groupcapable of conversion to an amino group) for diazotization and couplingto provide whichever of the groups A² and A³ is to react with a cyanurichalide, especially cyanuric chloride or fluoride, and additionallyhaving another amino group (or a group capable of conversion to an aminogroup) for reaction with the cyanuric halide and (3) a couplingcomponent to provide the group M.

Especially preferred coupling components for providing the group M are1-hydroxy-8-amino-naphthalene-3,5- and 3,6-disulphonic acid (K and Hacids respectively).

Suitable amine compounds (1) for diazotization to provide the terminalgroup are aniline, mono- and disulphonic acids, for example, orthanilic,metanilic and sulphanilic acids, 2-amino-5-methylbenzenesulphonic acid,2-amino-4-methyl benzenesulphonic acid, 2-chloro-4-aminobenzenesulphonic acid, 2-amino-3-chloro-1,5-disulphonic acid,2-amino-1,5-disulphonic acid,1-amino-3-(β-sulphatoethylsulphonyl)benzene and1-amino-4-(β-sulphatoethylsulphonyl) benzene, and α- or β-naphthylamineshaving up to 4 substituents, for example,2-aminonaphthalene-1,5-disulphonic acid,2-aminonaphthalene-4,8disulphonic acid and2-aminonaphthalene-3,6,8-trisulphonic acid.

Suitable diamines (2) for, on the other hand, reaction with a cyanurichalide followed by diazotization and coupling are2,4diaminobenzene-1-sulphonic acid, 2,5-diaminobenzene-1-sulphonic acid,and 2-amino-5-aminomethylnaphthalene-1-sulphonic acid.

In another preferred range of disazo dyes, at least one and morepreferably each of D¹ and D², independently, is a disazo chromophore ofthe formula (xix)

A²—N═N—M¹—N═N—E²  (xix)

wherein one of A², M¹ and E² is attached to the triazinylamino group; A²is as defined above;

M¹ is an optionally substituted 1,4-phenylene or 1,4naphthalene group;and

E² is an optionally substituted 1-4-phenylene or 1,4naphthalene group.

For each of M¹ and E² the optional substituent, independently, ispreferably at least one group selected from an alkyl (preferablyC₁₋₄alkyl), alkoxy (preferably C₁₋₄alkoxy), halo (preferably chloro) andan acylamino (preferably C₂₋₅acylamino) group and a sulphonic acid groupand a salt thereof.

Most of such chromophores will be brown in colour, as will a dye inwhich each of D₁ and D₂ is of the formula (xx).

More preferably, each of M¹ and E², independently, is a group of theformula (xx)

wherein the or each X³, independently, is alkyl, alkoxy, acetylamino oralkylsulphonylamino (and each alkyl group or moiety is preferablyC₁₋₄alkyl), and

p is zero or 1-4, more preferably zero or 1-3, still more preferablyzero, 1 or 2; or

a group of the formula (xxi)

wherein the or each X⁴, independently, is alkyl (preferably C₁₋₄alkyl),alkoxy (preferably C₁₋₄alkoxy), halo, sulphonic acid (or a salt thereof)or carboxyl (or a salt thereof) and r is zero or 1-4, preferably zero or1-3, still more preferably zero, 1 or 2.

Preferred starting materials for providing a chromophore of the formula(xix) are (1) a diazotizable amine component for diazotization andcoupling to provide the group A², (2) an amine compound for providingthe group M¹ onto which the diazotized amine compound (1) is to becoupled and which in turn is to be diazotized and coupled to a couplingcomponent and (3) a coupling component. Whichever of components (1)-(3)is to react with a cyanuric halide, especially cyanuric chloride orfluoride, for attachment of the chromophore to the triazinylamino groupwill have an amino group for reaction with the cyanuric halide.

Suitable diazotizable amine components (1) for diazotization to providethe group A² are those given above with reference to the formula (xvii).

Suitable diazotizable amine components (2) to which the diazotized aminecomponents (1) are coupled and which can be further diazotized areaniline, 2- or 3-methyl aniline, 2,5-dimethyl aniline, 2,5-dimethoxyaniline, 2-methyl-5-methoxy aniline, 3-aminoacetanilide and1-aminonaphthalene-6- and -7- sulphonic acids.

When coupling component (3) is the component for further reaction withthe cyanuric halide, preferred such coupling components are 2,5-dimethylaniline and 1-aminonaphthalene-6-, and -7- and -8- sulphonic acids.

In yet another preferred range of disazo chromophores, at least one andmore preferably each of D¹- and D²-, independently, is a coppered disazochromophore of the formula (xxii)

wherein each of A², X¹, X², B, s, t and u are as defined above.

Most such chromophores will be navy in colour, as will a dye in whicheach of D¹- and D²- is of the formula (xxii).

More preferably, the coppered disazo chromophore has the formula (xxiii)

wherein A², X¹ and s are as defined above.

Preferred starting materials for providing a metallized chromophore ofthe formula (xxii) are (1) a diazotizable amine component fordiazotization and coupling to provide the group A², (2) a compound towhich the diazotizable amine components (1) may be coupled and havingeach of an amino group for further diazotization and coupling and ahydroxy or methoxy group for metallization and (3) a coupling componentwhich is a naphthalene derivative containing an amino group for furtherreaction with a cyanuric halide especially cyanuric chloride orfluoride, and at an α-position a hydroxyl group or a free site such asto allow metallization.

Suitable amine compounds (1) for diazotization for providing the groupA² are those given above with reference to chromophore of the formula(xvii).

Suitable amine compounds (2) onto which the above diazo compounds arecoupled and which are further coupled to the coupling component (3) are1-amino-2-methoxy benzene, 1-amino-2-methoxy-5methyl benzene and1-amino-2,5-dimethoxy benzene.

Suitable coupling components (3) are H-acid and K-acid.

A dye in accordance with the invention may be prepared by a processwhich comprises reacting a piperazine of the formula (II)

wherein each of R³, R⁴, R⁵, x, y, a, b and z are as defined above, withan equimolar proportion of each of two reactive dyes respectively of theformulae (III)

wherein each of D¹, R¹ and X¹ are as defined above and X³ is a labileatom or group capable of reaction with an amine, and (IV)

wherein each of D², R² and X² is as defined above and X⁴ is a labileatom or group capable of reaction with an amine,

or, when each of D¹, R¹, X¹ and X³ is the same as D², R², X² and X⁴respectively,

with two moles of a reactive dye of the formula (II) or (IV) per mole ofthe piperazine of the formula (II),

to obtain the dye of the formula (I).

Although dye formulae have been shown in the form of their free acid inthis specification, the invention also includes dyes and processes usingdyes in the salt form, particularly their salts with alkali metals suchas the potassium, sodium, lithium or mixed sodium/lithium salt.

The dyes may be used for dyeing, printing or ink-jet printing, forexample, of textile materials and paper.

The process for colouration is preferably performed at a pH of 7.1 to13, more preferably 10 to 12. pH levels above 7 can be achieved byperforming the process for colouration in the presence of anacid-binding agent.

The substrate may be any of a textile material, leather, paper, hair orfilm, but is preferably a natural or artificial textile materialcontaining amino or hydroxyl groups, for example textile material suchas wool, silk, polyamides and modified polyacrylonitrile fibres, andmore preferably a cellulosic textile material, especially cotton,viscose and regenerated cellulose, for example, that commerciallyavailable as Tencel. For this purpose the dyes can be applied to thetextile materials at a pH above 7 by, for example, exhaust dyeing,padding or printing. Textile materials are coloured bright shades andpossess good fastness to light and wet treatments such as washing.

The new dyes are particularly valuable for colouring cellulosic textilematerials. For this purpose, the dyes are preferably applied to thecellulosic textile material at a pH above 7 in conjunction with atreatment with an acid-binding agent.

Preferred acid-binding agents include alkali metal carbonates,bicarbonates, hydroxides, metasilicates and mixtures thereof, forexample sodium bicarbonate, sodium carbonate, sodium metasilicate,sodium hydroxide and the corresponding potassium salts. The dyes benefitfrom excellent build-up and high fixation.

At least for cellulosic materials, dyeing may be carried out at asomewhat higher temperature of about 90° C., as compared with dyeingcarried out with conventional monochlorotriazine exhaust dyes which aregenerally dyed at temperatures of about 80° C. Although more energy isrequired, particularly improved migration is obtained.

The new dyes can be applied to textile materials containing aminegroups, such as wool and polyamide textile materials, from a neutral tomildly alkaline dyebath. The dyeing process can be carried out at aconstant or substantially constant pH, that is to say the pH of thedyebath remains constant or substantially constant during the dyeingprocess, or if desired the pH of the dyebath can be altered at any stageof the dyeing process.

The dyes may be in liquid or solid form, for example in granular orpowdered form.

We find surprisingly that such dyes provide the following advantageousproperties:

a) excellent build-up;

b) very strong dyeing;

c) good robustness to changes in dyeing conditions, especiallytemperature;

d) good wash off;

e) good fixation; and

f) good aqueous solubility.

Especially preferred embodiments of the invention will now be describedin more detail with reference to the following Examples in which allparts and percentages are by weight unless otherwise stated. Althoughpreparation and dyeing with any single dye is exemplified, particularadvantages can be seen when dyeing with mixtures of dyes.

EXAMPLE 1

A solution of a yellow dichlorotriazine dye (10) (0.021 mol) in water(315 mls) was added over 15 mins to a stirred solution of1-(2-aminoethyl) piperazine (15) (1.31 g, 0.01 mol) in water (100 mls)at room temperature and maintained at pH 10 by the addition of 2N NaOHsolution. After addition of the dye (10) the mixture was held at roomtemperature and pH 10 overnight.

The pH was adjusted to 6 with 2N HCl and the dye precipitated by theaddition of methylated spirit. The precipitated dye was filtered off anddried to give the expected dye (1) (9.4g) (λmax=426nm ε=55600 λ½=113nm).

Analytical data were in full agreement with the expected structure.

The above reaction may be represented by:

EXAMPLE 2

A mixture of a red dichlorotriazine dye (11) (0.02 mol) andN-(2-aminoethyl) piperazine (15) (0.01 mol) in water (500 mls) at roomtemperature was adjusted to pH 10 and maintained at pH 10 by theaddition of 2N NaOH solution whilst stirring overnight. The reactionmixture was adjusted to pH 7 and the dye precipitated by the addition ofmethylated spirit. The precipitate was filtered off and dried to givethe expected red dye (2) (15.2g) (λmax=505 nm ε=52550 λ½=92 nm). Allanalytical data were in full agreement with the expected structure.

The above reaction may be represented by:

EXAMPLE 3

Following exactly the same procedure as in Example 2, but replacing reddye (11) with red dye (12), yielded red dye (3) (22.4g) (λmax=516 nmε=55500 λ½=93 nm). Analytical data were in full agreement with theexpected structure.

The above reaction may be represented by:

EXAMPLE 4

Following exactly the same procedure as in Example 2, but replacing reddye (11) with red dye (13), yielded red dye (4) (32.4 g) λmax=510 nmε=74000 λ½=89 nm. Analytical data were in full agreement with theexpected structure.

The above reaction may be represented by:

EXAMPLE 5

Cyanuric chloride (1.4 g) in acetone (30 ml) was added dropwise to icewater (100 g). A solution of a navy disazo dye base (16) (15 g, MI 2986)in water (300 ml) was added dropwise at pH 6 and at 50C and stirred for6 hours at 5° C., and the mixture was allowed to assume roomtemperature, after which the mixture was screened through glass fibre togive a solution of the navy dichlorotriazine dye (14).

1-(2-Aminoethyl) piperazine (15) (0.33 ml) in water (50 mls) was addedto the reaction mixture and the pH adjusted and maintained at pH 10 with2N Na₂CO₃. The reaction mixture was stirred at room temperature and pH10 for 16 hours, then adjusted to pH 7 with 2N HCl.

The mixture was dialysed, evaporated to concentrate, and methylatedspirits (700 ml) was added to form a precipitate which was washed withmethylated spirits and dried to yield 5.7 g of a dye (5) (MI 2865; λmax613; εmax 94070; λ½ 112 nm).

All analytical data were in full agreement with the structure.

The above reactions may be represented by:

EXAMPLES 6-10

Each of the dyes prepared in Examples 1-5 was applied to cotton byexhaust dyeing at 80° C., 90° C. or 100° C., at a liquor:goods ratio of10:1 and in the presence of salt and soda ash. In each case, the dye wasfound to have excellent build-up, extremely high fixation efficiency andgood fastness properties.

EXAMPLES 11-22

When the navy dyebase of Example 5 of formula (16) was replaced byalternative navy dyebases, Dye-H, listed in the following Table,analogues of Example dye (5) shown in the Table following were prepared.Following the procedure of Examples 6-10, these dyes gave navy colouredcotton with excellent fastness and build-up properties, with highfixation efficiency.

In the following Table, each final tetrakisazo dye for which λmax andΣmax values are given had the formula

Example Dye-H λ_(max) ε_(max) 11

600 89000 12

614 100000  13

507 74000 14

601 78000 15

603 87000 16

600 17

605 18

592 100000  19

614 78000 20

602 56000 21

602 86000 22

606 66000

EXAMPLES 23-25

Other dyes which may be similarly prepared are as follows:

What is claimed is:
 1. A dye of the formula (I)

wherein: each of R¹, R², R³ and R⁴ independently, is H or an optionallysubstituted alkyl group; each of X¹ and X², independently, is a labileatom or group; each of x and y, independently, is 0 or 1 and at leastone of x and y is 1; each of a and b, independently, is 2 to 5; z iszero or is 1 to 4; and when each of x and y is 1, a>b; the or each R⁵,independently, is alkyl; each of D¹ and D², independently, is a monoazoor polyazo chromophore, or a metallized derivative thereof, providedthat the dye of the formula (I) is other than a dye of the formula (20)


2. A dye according to claim 1, wherein x is 0 and y is
 1. 3. A dyeaccording to claim 2, wherein b is 2 or
 3. 4. A dye according to claim1, wherein each of x and y is
 1. 5. A dye according to claim 4, whereina is 2 and b is
 3. 6. A dye according to claim 1, wherein z is zero. 7.A dye according to claim 1, wherein z is 1 and R⁵ is methyl or ethyl. 8.A dye according to any claim 1, wherein z is 2, each R⁵, independently,is methyl or ethyl and the R⁵s are substituted at the 2- and 5-positions respectively of the piperazine nucleus.
 9. A dye according toclaim 1, wherein each of X¹ and X², independently, is a halogen atom ora pyridinium salt.
 10. A dye according to claim 9, wherein each of X¹and X², independently, is F or Cl.
 11. A dye according to claim 10,wherein each of X¹ and X² is Cl.
 12. A dye according to claim 1, whereinD¹ and D² are the same as one another.
 13. A dye according to claim 1,wherein D¹ and D² are different from one another.
 14. A dye according toclaim 1 wherein at least one of D¹ and D² is a monoazo chromophore, or ametallized derivative thereof.
 15. A dye according to claim 14, whereineach of D¹ and D², independently, is an optionally metallized monoazochromophore of the formula (i) A—N═N—E  (i) wherein: one of A and E isattached to the reactive triazinylamino group; A is derived from adiazotizable amine; and E is derived from a coupling component.
 16. Adye according to claim 15, wherein A is an optionally substituted arylgroup and when A is attached to the triazinylamino group the attachmentmay be from the aryl group or from a substituent thereon; E is anoptionally substituted aryl or heteroaryl group and when E is attachedto the triazinylamino group the attachment may be from the aryl orheteroaryl group or from a substituent thereon, or E is anacetoacetamidoaryl group wherein the aryl moiety is optionallysubstituted and wherein the azo linkage in the formula (i), given anddefined in claim 15, is linked to the methylene group of theacetoacetamidoaryl group and when E is attached to the triazinylaminogroup the attachment may be from the aryl moiety or from a substituentthereon.
 17. A dye according to claim 16, wherein the group E isattached to the triazinylamino group in formula (I), A is a phenyl ornaphthyl group, optionally substituted by at least one of an alkyl,halo, cyano, hydroxy, aryloxy, alkylsulphonyl or arylsulphonyl group ora carboxylic or sulphonic acid group or salt thereof; and E is anoptionally substituted aryl or heteroaryl group selected from phenyl,naphthyl, pyrazolyl, pyrazolonyl, pyridyl, pyridonyl and pyrimidinylgroups or is an optionally substituted acetoacetamidoaryl group; whichsaid aryl or heteroaryl group or aryl moiety of the acetoacetamidoarylgroup is optionally substituted by an alkyl, phenyl, naphthyl or amino-(which may bear a C₁₋₄ alkyl group), amido- or sulphonamido-phenyl ornaphthyl group and E may be attached to the triazinylamino group fromthe said substituted alkyl group, phenyl or naphthyl group or phenyl ornaphthyl moiety of the said substituent; which said aryl or heteroarylgroup is further optionally substituted at least so as to provide thecoupling component from which the group E is derived with sufficientelectron donating capacity to allow the said coupling; and when A is anα-naphthol, which dye is optionally metallized.
 18. A dye according toclaim 17, wherein the group E is a phenyl or naphthyl group optionallysubstituted by an alkyl, alkoxy, ureido, acylamido, alkylsulphonyl,halo, hydroxyl or amino group, which amino group is optionallysubstituted by at least one alkyl group, or a carboxylic or sulphonicacid group or a salt thereof.
 19. A dye according to claim 17, whereinthe group E is a pyrazolyl, pyrazolonyl, pyridyl, pyridonyl orpyrimidinyl group and is substituted by a hydroxyl, mercapto or aminogroup, which amino group is optionally substituted by at least one alkylgroup.
 20. A dye according to claim 16, wherein the group A is attachedto the triazinylamino group in formula (I), A is a phenyl or naphthylgroup; which said phenyl or naphthyl group is optionally substituted byan alkyl, phenyl, naphthyl or amino- (which may bear a C₁₋₄ alkylgroup), amido- or sulphonamido-phenyl or naphthyl group and A may beattached to the triazinylamino group from the said substituent alkyl,phenyl or naphthyl group or phenyl or naphthyl moiety of the saidsubstituent; which said phenyl or naphthyl group of A is additionallyoptionally substituted by an alkyl, alkoxy or halo group or a carboxylicacid or sulphonic acid group or a salt thereof; and E is an aryl orheteroaryl group selected from phenyl, naphthyl, pyrazolyl, pyrazolonyl,pyridyl, pyridonyl and pyrimidinyl groups or is an optionallysubstituted acetoacetamidoaryl group; which said aryl or heteroarylgroup is optionally substituted at least so as to provide the couplingcomponent from which the group E is derived with sufficient electrondonating capacity to allow the said coupling; and when E is anα-naphthol group, the dye is optionally metallized.
 21. A dye accordingto claim 20, wherein the group E is a phenyl or naphthyl groupoptionally substituted by an alkyl, alkoxy, ureido, acylamino,alkylsulphonyl, halo, hydroxyl or amino group, which amino group isoptionally substituted by at least one alkyl group, or is a carboxylicor sulphonic acid group or a salt thereof.
 22. A dye according to claim20, wherein the group E is a pyrazolyl, pyrazolonyl, pyridyl, pyridonylor pyrimidinyl group substituted by a hydroxyl, mercapto or amino group,which amino group is optionally substituted by at least one alkyl group.23. A dye according to claim 17, wherein A is an optionally substitutedphenyl or naphthyl group (Ar) and E is an acetoacetamidoaryl group suchthat at least one of D¹- and D²- is a chromophore of the formula (iii)

wherein: the or each of R⁶ is alkyl, alkoxy, halo, H₂NCONH, CH₃CONH orSO₃H (or a salt thereof; R¹¹ is hydrogen or alkyl; p is zero or 14; Aris an optionally substituted phenyl or naphthyl group or is achromophore; and the unsubstituted bond {circle around (1+L )} indicatesa link to a triazinylamino group in the formula (i).
 24. A dye accordingto claim 20 wherein: E is an acetoacetamidoaryl group and A is anoptionally substituted phenylene group such that at least one of D¹- andD²- is a chromophore of the formula (iv)

wherein B is an optionally substituted aryl group; the or each R⁶ isalkyl, alkoxy, halo, H₂NCONH, CH₃CONH or SO₃H (or a salt thereof); R¹¹is hydrogen or alkyl; p is zero or 1-4; and the unsubstituted bond{circle around (1+L )} indicates a link to a triazinylamino group in theformula (I).
 25. A dye according to claim 23, wherein p is zero or is 1,2 or
 3. 26. A dye according to claim 17, wherein, in at least one of D¹and D², E is an optionally substituted phenylene group and therebyprovides, in the dye, at least one chromophore of the formula (v)

where in: A¹ is a phenyl or naphthyl group, optionally substituted by atleast one of an alkyl, halo, cyano, hydroxy, aryloxy, alkylsulphonyl orarylsulphonyl group or a carboxylic or sulphonic acid group (or a saltthereof); the or each R⁶, independently, is alkyl, alkoxy, halo,H₂NCONH, H₃CCONH or SO₃H (or a salt thereof); p is zero or is 1-4; andthe unsubstituted bond {circle around (1+L )} indicates a link to atriazinylamino group in the formula (I).
 27. A dye according to claim26, wherein p is zero or p is 1, 2 or
 3. 28. A dye according to claim27, wherein p is 1 or
 2. 29. A dye according to claim 27, wherein eachof D¹- and D²-, independently, is of the formula (vi)

wherein A¹ is a phenyl or naphthyl group, optionally substituted by atleast one of an alkyl, halo, cyano, hydroxy, aryloxy, alkylsulphonyl orarylsulphonyl group or a carboxylic or sulphonic acid group (or a saltthereof); R⁷ is alkyl, alkoxy, halo, H₂NCONH or H₃CCONH; and R⁸ is H,alkyl, alkoxy or halo.
 30. A dye according to claim 29, wherein R⁷ isH₂NCONH— and R⁸ is H.
 31. A dye according to claim 29, wherein A¹ is aphenyl or naphthyl group substituted by at least one SO₃H group, or asalt thereof.
 32. A dye according to claim 26, wherein, in the formula(I), x is zero, y is 1 and b is 2 or
 3. 33. A dye of the formula (I)


34. A dye according to claim 26, wherein E is an optionally substitutedheteroaryl group.
 35. A dye according to claim 34, wherein E has theformula (vii)

wherein the or each R⁶ is alkyl, alkoxy, halo, H₂NCONH, CH₃CONH or SO₃H(or a salt thereof); p is zero or 1-4; X is OH or NH₂; and R⁹ is methyl,carboxyl or methoxycarbonyl; or

wherein R¹² is hydrogen, C₁₋₄ alkyl or phenyl; R¹³ is hydrogen, C₁₋₄alkyl, CONH₂, CN or CH₂SO₃H, and R¹⁴ is C₁₋₄ alkyl or phenyl; or

wherein each of P, Q, and R, independently, is hydrogen, C₁₋₄ alkoxy,hydroxyl, C₁₋₄ alkythio, mercapto, amino, C₁₋₄ alkylamino or (di-C₁₋₄alkyl) amino; and wherein, in each of formula (vii)-(ix), the bond{circle around (2+L )} is attached to the monoazo group in the formula(i) A—N═N—E  (i) wherein: A is derived from a diazotizable amine; and Eis derived from a coupling component.
 36. A dye according to claim 17,wherein E is a heteroaryl or heteroaralkyl group.
 37. A dye according toclaim 36, wherein E is a heteroaryl group of the formula (x)

wherein the or each R⁶ is alkyl, alkoxy, halo, H₂NCONH, CH₃CONH or SO₃H(or a salt thereof); p is zero or 1-4; X is OH or NH₂; and R⁹ is methyl,carboxyl or methoxycarbonyl; or E is a hetero or heteroaralkyl group ofthe formula

wherein R¹² is hydrogen, C₁₋₄ alkyl or phenyl; R¹³ is hydrogen, C₁₋₄alkyl, CONH₂, CN or CH₂SO₃H; and q is zero or is 1-4; and in each of theformula (x) and (xi), the bond {circle around (1+L )} indicates a linkto a triazinylamino group in the formula (I), and the bond {circlearound (2+L )} is attached to the monoazo group in the formula (i)A—N═N—E  (i) wherein: A is derived from a diazotizable amine; and E isderived from a coupling component.
 38. A dye according to claim 17,wherein E is a hydroxynaphthyl group optionally substituted by at leastone sulphonic acid group or a salt thereof and optionally furthersubstituted by a halogen atom, a hydroxyl group, a methyl group or anacylamino group.
 39. A dye according to claim 38, wherein E is ahydroxynaphthyl group substituted by at least one sulphonic acid groupor a salt thereof.
 40. A dye according to claim 38, wherein, in theformula (I), x is zero, y is 1 and b is 2 or
 3. 41. A dye according toclaim 38, wherein the group E has the formula (xiii)

or has the formula (xiv)

wherein in each formula (xiii) and (xiv) the or each R¹⁵ is halogen,methyl, acylamino or SO₃H or a salt thereof and p is zero or 1-4; thebond {circle around (1+L )} indicates a link to a triazinylamino groupin the formula (I); and the bond {circle around (2+L )} is attached tothe monoazo group in the formula (i) A—N═N—E  (i) wherein: A is derivedfrom a diazotizable amine; and E is derived from a coupling component.42. A dye of the formula (2)


43. A dye of the formula (3)


44. A dye of the formula (4)


45. A dye according to claim 15, wherein each of D¹- and D²-,independently, is a coppered monoazo chromophore of the formula (xv)

wherein X¹ is a sulphonic acid group (or a salt thereof), a carboxylgroup (or a salt thereof), or an alkyl or alkoxy group or a halogenatom; X² is a sulphonic acid group; B¹ is an optionally substitutedphenylene or naphthalene group linked to the naphthalene nucleus eitherdirectly or through an optional substituent and linked to thetriazinylamino group either directly or through an optional substituent;s is zero or is 1-4; t is zero or is 1-3; u is zero or 1; and theunsubstituted bond {circle around (1+L )} indicates a link to atriazinylamino group in the formula (I).
 46. A dye according to claim45, wherein the coppered monoazo chromophore has the formula (xvi)

where X¹ and s are as defined in claim
 45. 47. A dye according to claim1, wherein at least one of D¹ and D² is a disazo chromophore, or ametallized derivative thereof.
 48. A dye according to claim 47, whereineach of D¹ and D², independently, is a disazo chromophore of the formula(xvi) A²—N═N—M—N═N—A³  (xvi) wherein one of A² and A³ is attached to thetriazinylamino group and each of A² and A³, independently, is a phenylor naphthyl group, optionally substituted by at least one group,independently, selected from sulphonic acid (or a salt thereof,carboxylic acid (or a salt thereof, alkyl, alkoxy, acylamino, halo,alkylsulphonyl and alkylsulphonylamino groups; and M is a naphthylylenegroup substituted by at least a hydroxyl and an amino group andoptionally substituted by at least one sulphonic acid group.
 49. A dyeaccording to claim 48, wherein M is a group of the formula (xviii)

wherein the sulphonic acid group in the 8-amino-substituted ring is inthe 5- or 6- position.
 50. A dye according to claim 48, wherein each ofD¹ and D², independently, is a disazo chromophore of the formula (xix)A²—N═N—M¹—N═N—E²  (xix) wherein one of A², M¹ and E² is attached to thetriazinylamino group; A² is as defined in claim 48; M¹ is 1,4-phenyleneor 1,4-naphthalene group, optionally substituted by at least one groupselected from and alkyl, alkoxy, halo and arylamino group and asulphonic acid group and a salt thereof; and E¹ is a 1,4-phenylene or1,4-naphthalene group, optionally substituted by at least one groupselected from an alkyl, alkoxy, halo and an arylamino group and asulphonic acid group and a salt thereof.
 51. A dye according to claim50, wherein each of M¹ and E², independently, is a group of the formula(xx)

wherein the or each X³, independently, is alkyl, alkoxy, acetylamino oralkylsulphonylamino or sulphonic acid group or salt thereof, and p iszero or 1-4; or a group of the formula (xxi)

wherein the or each X⁴, independently, is alkyl, alkoxy, halo, sulphonicacid (or a salt thereof) or carboxyl (or a salt thereof) and r is zeroor 1-4.
 52. A dye according to claim 47, wherein each of D¹- and D²-,independently, is a coppered disazo chromophore of the formula (xxii)

wherein A² is a phenyl or naphthyl group, optionally substituted by atleast one group, independently. selected from sulphonic acid (or a saltthereof), carboxylic acid (or a salt thereof), alkyl, alkoxy, acylamino,halo, alkylsulphonyl and alkylsulphonylamino groups; X¹ is a sulphonicacid group (or a salt thereof), a carboxyl group (or a salt thereof), oran alkyl or alkoxy group or a halogen atom; X² is a sulphonic acidgroup; B¹ is an optionally substituted phenylene or naphthalene grouplinked to the naphthalene nucleus either directly or through an optionalsubstituent and linked to the triazinylamino group either directly orthrough an optional substituent; s is zero or is 1-4; t is zero or is1-3; and u is zero or
 1. 53. A dye according to claim 52, wherein thecoppered disazo chromophore has the formula (xxiii)

wherein A² is a phenyl or naphthyl group, optionally substituted by atleast one group, independently, selected from sulphonic acid (or a saltthereof), carboxylic acid (or a salt thereof), alkyl, alkoxy, acylamino,halo, alkylsulphonyl and alkylsulphonylamino groups; X¹ is a sulphonicacid group (or a salt thereof), a carboxyl group (or a salt thereof), oran alkyl or alkoxy group or a halogen atom; and s is 1 or
 2. 54. Aprocess for preparing a dye of the formula (I), given and defined inclaim 1, which process comprises reacting a piperazine of the formula(II)

wherein each of R³, R⁴, R⁵, x, y, a, b and z is as defined in claim 1,with an equimolar proportion of each of two reactive dyes respectivelyof the formulae (III)

wherein each of D¹, R¹ and X¹ are as defined in claim 1 and X³ is alabile atom or group capable of reaction with an amine, and (IV)

wherein each of D², R² and X² is as defined in claim 1 and X⁴ is alabile atom or group capable of reaction with an amine, or, when each ofD¹, R¹, X¹ and X² is the same as D², R², X² and X⁴ respectively, withtwo moles of a reactive dye of the formula (III) or (IV) per mole of thepiperazine of the formula (II), to obtain the dye of the formula (l).55. A process for the colouration of a substrate, which processcomprises applying to the substrate, at a pH above 7, a dye according toclaim
 1. 56. A process according to claim 55, wherein the dye is appliedto the substrate by exhaust dyeing, padding or printing.